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NICT REPORT 11white paper. Additionally, for large-capacity data collection networks consisting of a large-scale mesh of many wireless terminals, we extended the Layer 2 Routing (L2R) spec-ification as an IEEE 802.15.10 recommended practice in fiscal year 2016 and successfully demonstrated data concatenation, virtualiza-tion, and other functional enhancements. Then, as an agricultural application of an ul-tra-low-energy network using battery-driven wireless terminals, we successfully demon-strated low-energy wireless operation for both data collection and control in a real ag-ricultural field.Wireless network reinforcement technologyWe proposed a PHY/MAC system for dis-tributed inter-terminal communications and took a leading role in formulating the IEEE 802.15.8 standard. We also developed an im-pulse-radio ultra-wideband (IR-UWB) posi-tioning system and promoted system verifi-cation trials in Southeast Asia. In addition, we studied latency-guaranteed wireless network technology (maximum allowed latency: 20 ms) for transmitting on-vehicle sensor data for application to the IEEE 802.15.8 UWB sys-tem. Furthermore, in relation to latency-guar-anteed, multi-hop relay control communica-tion systems for ensuring the safe operation of non-line-of-sight robots or drones, we de-signed and developed a frequency-redun-dant-type system using a new robot band and successfully performed a verification ex-periment targeting the flying of drones. We also conducted joint research with a major power infrastructure operator toward practi-cal deployment of this technology.Global optical satellite commu-nications network technologyWe performed optical satellite commu-nications experiments between a low-orbit satellite and a ground station using an on-board laser communication terminal called Small Optical TrAnsponder (SOTA), and successfully performed the world’s first ba-sic quantum-communications experiment for a 50-kg-class micro-satellite (Fig.2). This achievement was published in Nature Photonics and turned out to be more suc-cessful than expected.Next, with a view to performing space communication demonstrations using Engi-neering Test Satellite IX (ETS-IX), we com-pleted the preliminary design for the on-board equipment of ultra-high-speed optical communication equipment called HIgh speed Communication with Advanced Laser Instrument (HICALI) for achieving 10-Gbps-class transmission speeds between a station-ary satellite and ground station as a world’s first (Fig.3). Additionally, after working on the development of ultra-high-speed optical sat-ellite communication devices for on-board use in the form of consigned research, we use the results of this work to establish a screen-ing process for space-environment tolerance tests for commercial off-the-shelf (COTS) op-tical communication devices.We also participated in standardization ac-tivities for space laser communications in the Consultative Committee for Space Data Sys-tems (CCSDS) founded by major space agencies around the world and contributed to the first official report for space laser com-munications.Space/ocean broadband satellite communications network tech-nologyThe Wireless Networks Research Center led the drafting of overall requirements for ETS-IX communication missions, promoted R&D of flexible satellite traffic control technol-ogy and on-board fixed multi-beam commu-nication equipment as the representative re-search institution, and completed a preliminary design. Additionally, with regard to high-efficiency operation and control tech-nology for a non-conventional RF/optical hybrid satellite communication system pro-posed by NICT for ETS-9 demonstrations, we studied a basic model in fiscal year 2016 and designed a conceptual model of a control system in which a Network Operation Center (NOC) manages frequency and beam varia-tion and RF/optical feeder link switching (Fig.4). We also fabricated the basic compo-nents of a simulator for testing these func-tions. In addition to the above, we per-formed a series of measurements of mobile-terminal propagation characteristics in the Ka-band using the WINDS satellite.In the area of international standardization, we participated in the standardization of an integrated Mobile Satellite Services (MSS) system within the Asia-Pacific Telecommuni-ty (APT) as part of the APT Wireless Group (AWG) and contributed to the completion of a new report reflecting NICT proposals.Fig.4 : Conceptual model of high-efciency control systemFig.2 : World’s rst satellite-to-ground, quantum-cryptography basic experiment using SOTAFig.3 : Basic conguration of optical feeder link experiment using ETS-9Research and Development